I didn't get the same result. I used the relativistic rocket equation [1], and the change in rapidity from 0 to 0.998c is about 3.5, which means a total change of rapidity of about 7 (static to full speed and then back to static). Assuming perfect hydrogen->helium fusion engine (specific impulse=0.12c) the ratio between initial mass and final mass is 10^25. For comparison the mass of the earth is about 0.6*10^25, or in other words, if you want to send only 2kg of load to this star, you need fuel as much as the mass of the earth.

[1] https://en.wikipedia.org/wiki/Relativistic_rocket